Follow your power cord back into your rig. The box it enters is most probably your power transfer switch. When you find the box have someone turn the power off then on the box should make an audible click or thump sound. With power disconnected remove the cover and visually inspect for melted wires. Tighten all connections. This is a maintenance item that really should be done once a year anyway.
Having your AC on when switching from shore to generator is not recommended but in most cases would only blow the breaker on the generator or in the power panel.
